Mattress extension



FIG. 1 is a front perspective view of a mattress extension.

FIG. 2 is a front view thereof, with the rear view being a mirror imagethereof.

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a right side elevational view thereof, with the left side viewbeing a mirror image thereof.

CLAIM The ornamental design for a mattress extension, as shown anddescribed.